All-metal-airplane structure



. Oct. 20, 1925.

F. E. LOUDY ALL METAL AIRPLANE STRUCTURE Filed Nov. 2, 1921 PatentedOct. 20, 1925.

UNITED STATES FLAVIUS E. LOUDY, OF IMOIBILE, ALABAMA.

ALL-METAL-AIRPLANE STRUCTURE.

Application filed November 2, 1921.

T 0 all whom it may concern Be it known that I, FLAvrUs E. LOUDY, acitizen of the United States, residing at Mobile, in the county ofMobile and State of Alabama, have invented certain new and usefulImprovements in All-Metal-Airplane Structures, of which the following isa specification.

The invention relates to airplanes of the all-metal type, the primaryobject being to provide a structure which is fundamentally differentfrom that of the all-metal planes heretofore produced, and whichpossesses several advantages over the latter.

Specifically, it is the purpose of the present invention to produce anairplane of the type mentioned Whose external form and other features ofdesign will conform strictly to the conventional practice and at thesame time to effect an economy in labor and cost of material.

Accomplishment of the foregoing object is permitted by the fact thatreadily available commercial articles of metallic building material maybe employed in the proposed construction. For instance, strips of sheetmetal, channel beams, and the like, may be utilized for the purpose.

It is an object also to provide a fuselage construction which will bevery strong and durable, and which Will afford a maximum amount ofunobstructed interior space for the accommodation of the pilot,passengers and cargo.

Other objects and advantages may appear as the following specificdescription is read in connection with the accompanying drawings, inwhich:

Figure 1 is a side elevation of the fuselage of a single-seater biplaneof the tractor type constructed in accordance with the invention, thewings being omitted in this view;

Figure 2 is a plan view of the fuselage;

Figure 3 is a transverse sectional view on line 3-3 of Figure 1;

Figure 4 is a longitudinal section through a portion of the fuselage online 4.4 of Figure 3, and drawn on a large scale to show the minutedetails of construction;

Figure 5 is a similar detailed sectional view taken on line 55 of Figure4;

Figure 6 is a similar view on line 66 of Fkiigure 1, showing a top seamin the outer s n;

For the purpose of illustration, the inven- Serial No. 512,275.

tive idea has been shown applied to the construction of a particulartype of airplane, but it is to be understood that its principles may beembodied in various other types of craft. t may be pointed out also thatcertain details of the construction are merely illustrative and may bemodified in practice without departing from the scope of the appendedclaims.

Referring to the drawings, it will be noted, upon reference to Figures 1to 3 in particular, that the fuselage consists essentially of an outerskin 15, an inner skin 16, a plurality of longrons 17, interposedbetween skins, and a plurality of segmental bulkheads or ribs 18, whichare likewise disposed between skins and are connected with the longrons.

This construction will give more strength to the fuselage throughout itsentire length without the use of any cross braces or bulkheads, whichwould obstruct the interior and divide it into a number of restrictedcompartments.

Instead, the fuselage will have one long interior chamber of greatcapacity. The presence of such a large, continuous space within thefuselage is a decided advantage in any type of aircraft, especially inthose ships which are designed for carrying heavy loads of cargo orpassengers. In military airplanes, this interior space may be utilizedfor the storage of aerial bombs or other munitions.

The outer skin 15 may be formed conveniently by pressing two largesheets of metal into such shape that each forms half of the fuselage andhas the proper streamline external configuration. The best mechanicalconstruction seems to be that shown most clearly in Figures 2 and 3,wherein the two plates are joined at the top and the bottom of thefuselage by longitudinal seams 19 and 20. Each plate thus forms oneside-half of the entire outer skin.

At this point it may be well to state that I do not intend to be limitedto the use of precisely two plates, nor to the location of the seams atthe top and bottom of the fuselage. A. greater or lesser number ofplates might be employed and the form and arrangement might be variedwithin the spirit of the present invention. Furthermore, it is notnecessary that the plates shall be formed by pressing sheet metal intothe desired form. They may be produced by casting molten metal or bysome other suitable and economical method.

When constructing the side plates of the outer skin, stationary parts 21of the em pennage assembly, such as the stabilizers, etc., may be formedon the tail portions of these plates. Also, bases 22 and 23 for theattachment of the upper and lower wings respectively may be formed byproviding extensions on the side plates of the outer skin. Each. platewill afford half of each one of these bases, and the construction shouldbe such that the latter will have the streamline form shown in Figure 2.

It may be found convenient to leave an opening 24: in the nose of thefuselage for the insertion of the power plant. The engine cowl, whenapplied, should complete the streamline configuration of the fuselagenose as indicated by the dotted lines 25 in Figure 1. An opening 26 isshown in Figures 1 and 2 at the appropriate location for the pilotscockpit. In other types of ship, other openings may be necessary. Theirnumber and disposition are immaterial so far as the principles of thepresent invention are concerned.

In Figure 6 the details of the seam between side plates of the outerskin, which has been adopted for the purpose of disclosure, are shown.This type of seam should prove quite efficient. It will bind the platessecurely together and will keep their outer surfaces flush where theyjoin so as to preserve the smooth streamline surface. The details of theseam will be described more fully hereinafter. It is essential to theclearness of the description that other more important parts of thefuselage be described in the meantime.

The inner skin 16 is preferably formed by a series of connected plates27 which are trapezoidal in general form and are bent transversely intoparallelism with the outer skin. These channels are secured together attheir meeting edges by seams 28, which are shown in detail in Figures 4.and 5. The longrons 17 and bulkheads 18, which separate the inner andouter skins are formed preferably by appropriate lengths of channelbeams. Each of these members may consist of two channel beams placedback to back and secured tog-ether by means of rivets 29. The longronsare nearly straight and are of integral construction from one end of thefuselage to the other, whereas the bulkheads are curved in conformity tothe transverse curvature of the skins 15 and 16 and are just long enoughto bridge the space between adjacent longrons. In order to minimizeweight, the bulkheads, which are not subjected to the same stress as thelongrons, may be provided with perforations 30 in their web portions. Ithas been found to be practical to secure the flanges of the longrons andbulkheads to the outer skin by means of rivets 31 and to the inner skinby means of screws 32, but it is obvious that some other form ofattaching means might be adopted instead.

As shown in Figures 3 to 6, the outer skin is thicker than the innerskin. This is preferable in most instances, due to the greater stressand wear to which the outer skin is subjected. This is a feature,however, which is not binding. Any desired alterations in the relativethickness of this skin may be made to meet the requirements of practice.

Referring particularly to Figure 5, it will be noted that the ends ofthe bulkheads 18 are pinched in order that they may fit snugly betweenthe flanges of adjacent longrons.

In Figures 3 and 6 the uppermost and lowermost bulkheads are representedas having depressions formed contiguous to the respective top and bottomseams of the outer skin for the reception of those parts of the seamstructure which would otherwise cause the seams to bulge outwardly.Referring to Figure 6 in particular, it will be observed that each seamis formed by bending the meeting edges of both side plates inwardly andthen back into parallelism with the maj or portions of these plates. Thebent edges are indicated at 33. A binding strip 34 is crimped around theedges 33 of the side plates. then rivets 35 are passed through the sideplates, the binding strip, and the flanges of the adjoining bulkhead soas to complete the formation of a very tight, durable seam.

By cutting the panels 27 of the inner skin so that their meeting edgeswill extend along the longrons and bulkheads, the formation of seamswill be facilitated, The channel beams which unite to form each longronor bulkhead are of such cross-sectional shape that longitudinal grooves26 will b pr vided between the flanges where they turn outward from theweb. These grooves are shown clearly in Figures i and 5. The meetingedges of adjacent panels may be bent inwardly as at 37 so as to projectinto the corresponding groove 36 of the longron or bulkhead, as the casemay be, and a binding strip 38, which is U-shaped in crosssection, maybe mounted within the groove and crimped around the edges of the panels.

It has been stated throughout the specification that the various partsof the structure are metallic in nature. While the principal object inview has been to produce a satisfactory all-metal plane, it is not mydesire to be confined to the use of metal. Future developments may makeit practical to use some other kind of structural material possessingsuch qualities that it may be made into the various spars, ribs,longrons, bulkheads and skins, which form the essential elements of thepresent invention.

I claim:

1. In an aircraft fuselage, an outer skin composed of two side platesco'extensive in length with the length of the fuselage and seamedtogether along the top and bottom of the fuselage, said plates beingshaped to provide a vertical offset forming an abutment for wings.

2. In an aircraft fuselage, an outer skin composed of two side platesco-extensive in length with the length of the fuselage and seamedtogether along the top and bottom of the fuselage, said plates beingshaped to provide a vertical streamlined abutment for wings.

3. In an aircraft fuselage, an outer skin composed of two side platesco-extensive in length with the length of the fuselage and seamedtogether along the top and bottom of the fuselage, said plates beingshaped to provide upper and lower vertical abutments for wings.

4. In an aircraft fuselage, an outer skin composed of two side platesco-extensive in length with the length of the fuselage and seamedtogether along the top and bottom of the fuselage, the longitudinal edgeof said plates being bent inwardly and away from each other, and aC-shaped binding strip clinched around such bent edges.

5. In an aircraft fuselage an outer skin composed of two side platesco-extensive in length with the length of the fuselage and seamedtogether along the top and bottom of the fuselage, open center bulkheadsinternally bracing said plates, and an inner skin composed of plateshaving meeting edges resting against said bulkheads and fastenedthereto.

6. In an aircraft fuselage, an outer skin composed of two side platesco-extensive in length with the length of the fuselage and seamedtogether along the top and bottom of the fuselage an inner skin, andlongrons interposed between and connecting said skins and each composedof a pair of channel beams having their webs united and having theoppositely extending flanges thereof fastened to the outer and innerskins.

7. In an aircraft fuselage, an outer skin composed of two side platesco-extensive in length with the length of the fuselage and seamedtogether. along the top and bottom of the fuselage an inner skin, andlongrons interposed between and connecting said skins and each composedof a pair of channel beams having their webs united and having theoppositely extending flanges thereof fastened to the outer and innerskins and segmental bulkheads of sheet metal flanged and having thesegments thereof compressed inwardly and fitted and fastened between theflanges of the longrons.

8. In an aircraft fuselage, outer and inner skins, and internal bracingmembers each composed of channel beams having their webs united and theoppositely extending flanges thereof fastened to said outer and innerskins.

9. In an aircraft fuselage, outer and inner skins, internal bracingmembers each composed of channel beams having their webs united and theoppositely extending flanges thereof fastened tosaid outer and innerskins, and outer bracing members having flanges fastened to said outerand inner skins and made in sections terminally fastened to the firstnamed bracing memhers. 3 l l 10. In an aircraft fuselage, a frame ofstreamline form including longrons and segmental bulkheads connectedtogether, and an inner skin comprising a plurality of segmental plateshaving their edges extending along adjacent longrons and bulkheads,adjoining edges of the said plates being joined together.

In testimony whereof I have affixed my signature.

FLAVIUS '1'3. LOUDY.

